React State Management: When to Use useState and useReducer Hooks

React Hooks are a powerful tool that allows developers to manage state and side effects in functional components. Two of the most commonly used hooks are useState and useReducer. Both hooks allow you to manage state in your components, but they are used in different situations and provide different functionality.

useStateis the most basic hook for managing state in a React component. It allows you to set and update a single piece of state. The hook takes in an initial value and returns an array with two elements: the current state and a function to update the state.

const [count, setCount] = useState(0);

In this example, count is the current state and setCount is the function to update the state. To update the state, you simply call the setCount function and pass in the new value.

setCount(count + 1);

useStateis great for simple state management, such as keeping track of a form input or a toggle button. But it can become cumbersome when managing more complex state.

useReduceris a more powerful hook for managing state in a React component. It allows you to manage complex state and handle multiple actions in a single function. The hook takes in a reducer function and an initial state, and returns an array with two elements: the current state and a dispatch function.

const [state, dispatch] = useReducer(reducer, initialState);

The reducer function takes in the current state and an action, and returns the new state. The dispatch function is used to trigger the reducer function and update the state.

function reducer(state, action) {
  switch(action.type) {
    case 'increment':
      return { ...state, count: state.count + 1 };
    case 'decrement':
      return { ...state, count: state.count - 1 };
    default:
      return state;
  }
}

dispatch({ type: 'increment' });

In this example, the reducer function is handling two different actions: 'increment' and 'decrement'. The dispatch function is used to trigger the appropriate action and update the state.

useReduceris useful for managing complex state and handling multiple actions in a single function. It allows you to centralize your state management and keep your components simple.

In conclusion, useStateand useReducerare both React Hooks used for managing state in functional components. useState is used for simple state management and allows you to set and update a single piece of state, while useReduceris used for complex state management and allows you to handle multiple actions in a single function. The choice between the two hooks depends on the complexity of your state and the number of actions you need to handle.